Treatment of liquids such as milk with rays, more particularly with ultra-violet rays



Aug. 21, 1928. 1,681,538

F. HOFFMANN TREATMENT OF LIQUIDS SUCH As MILK WITH RAYS, MOREPARTICULARLY WITH ULTRA VIOLET RAYS Filed Nov. 28, 1927 5 s i1 2 I K f1/ 15 1 I i 15 V16 t H gs 14 1E ,i W

! EM -k ZV TZIQ Patented Aug. 21, 1928.

UNITED STATES 1,681,538 PATENT OFFICE...

, rmz norrmnn, or VIENNA, Aus'rnn.

TREATMENT OF LIQUIDS SUCH AS MILK WITH RAYS, MORE PARTICULARLY WITHULTRA-VIOLET RAYS.

Application filed November 28, 1927, Seriai No. 236,854, and in AustriaOctober 30, 1926.

It has often-been proposed to treat liquids with rays of short wavelength. In order to obtain a uniform action of the rays upon the liquidit is necessary tv split up the latter into thin layers. This wasdonefor example by allowing the liquid to flow between two glass partitions,such as plates or cylinders, which were more or less permeable withrespect tothe rays, thus irradiating the liquid through theglass. Insuch a case however, the portion of the rays absorbed by the glass islost.

The method and corresponding apparatus described hereinafter make itpossible to treat liquids with rays of any kind, for instance withultra-violet rays, without a portion of the radiation being lost byabsorption. According to the method forming the subject matter of thepresent invention, the liq- 2e uid is first of all converted into a thinlayer and thereupon led over a very interrupted surface, such as forinstance a grid. In such a case it not only flows away over the gridbars, but owing to the surface tension also over the interruptions inthe surface, so that it forms a continuous layer (thin film of milk),which is not enclosed by walls, but flows away freely. Layers of liquidconstituted in this way can now be treated with rays, without anylossby'absorption. I

For the purpose of obtaining the full efiect of the radiation it isadvisable to make the grid in the form of a .for instance cylindricalhollow body and to locate the source of the '35 rays in the central axisof the cylinder. The

diameter of the hollow body and'at the-same time the distance of thesource of-the rays from its inner surface is so chosen that as powerfulan action as possible on the liquid 40 is ensured. The material of whichthe interrupted surface is made depends in the first lace upon thecharacteristics of the liquid to treated; for milk, the treatment ofwhich is the chief consideration in this case, use may be made of sheetmetal. The means used for generating the rays in the present method isan electric light source, which is rich in ultra-violet rays, such asfor instance a lamp of the Farlan- Moore type, i. e. a kind of Geisslertube of pure fused rockcrystal, preferably provided with a filling ofinert gas and condenser electrodes. The tubes can be operated with highvoltage alternating current of low, medium or II high frequency asdesired. Instead of this means for generating the rays use mi ht howeveralso be made for instance of t e wellknown Uviol lamp. The method andapparatus forming the subject matter of the present invention arehowever also suitable for other rays than the ultra-violet.

. The accompanying drawing illustrates diagrammatically in longitudinalsection one constructional form of the apparatus used for carrying outthe method in question.

The stand 1 supports by means of the arms 2 and 3 on the one hand abulb-shaped hollow body 4, and on the other hand a sleeve 5 arrangedaround the wire grid 14. On the bulb 4 is provided a funnel-shapedsupplying trough 6 for the milk, which enters the apparatus through pipe7 and tap 8. The

trough 6 is rigidly connected by the arms 9 and 9' with an annular part10 and is open at the top and bottom; the diameter of the upper apertureis considerably larger than that of the lower. The annular part 10embraces the neck of the bulb 4 and can slide up and down on it. Closeto its upper edge it is provided outside with a screw-thread, whichengages so with a corresponding screw-thread on the inner surface of anut 11. This nut 11 is also slid onto the neck of the bulb 4 and reststhere on the projection 12, on which it is freely rotatable. When thenut 11 is turned, the annular part 10 is accordingly lifted or loweredand with it the trough 6 because it is rigidly connected with theannular part. 10 by the arms 9, 9'. As the lower aperture of the trough6 reaches right down to the outer surface of the bulb 4, by the raisingof the trough 6 the slit 13between the lower edge of the trough and thewall of the bulb becomes larger and when the trough is lowered becomessmaller.

The milk enters first into the trough 6, passing from here'through theslit 13 to the surface of the bulb 4, becomes distributed over thelatter in a thin' layer and then flows over the grid 14, bridging overthe various 10o meshes of the grid with a thin film of liquid. Insidethe grid is located the means 15 gener? ating the rays, the electriccurrent operating the same passing through the hollow neck of the bulb 4by means of the wires 18, 18'. The 106 treated milk flows into thecontainer 16, from which it finally emerges through 17. In many cases,as for instance in the case of milk, it is undesirable owing to theformationof ozone, to allow air to have free access to the 11 to beimmersed under the surface of the milk it is possible to shut off theadmission of air from below. It is however also possible to exclude thepossibility of the formation of ozone by passing an inert gas into theinterior of the sleeve. In order fully to utilize the rays passingthrough the grid 14, it is advisable to make the sleeve 5 of a material.which reflects the rays or to make its inner surface capable ofreflecting in a known manner.

The described treatment has numerous effects, in the case of milk, inaddition to sterilizing it, its vitamin content is also increased.

It is clear that it ispossible by means of the invention to treat theliquid in as thin a layer as desired by means of a simple device, whileutilizing the energy of the rays to the fullest extent.

I claim- 1. Device for irradiating liquids more especially withultra-violet rays, comprising in combination a hollow body, a gridforming an extension of the latter, a source of light-rays arrangedWithin the said grid, and a vertically adjustable trough, open at itslower purpose specified.

2. Device for irradiating liquids more especially with ultra-violetrays, comprising in combination a hollow bulb-shaped body, a cylindricalgrid forming an extension of the latter, a sourceof light-rays arrangedwithin the said grid, and a vertically adjustable trough, open at itslower end, surrounding the bulb-shaped body, the lower end of saidtrough being in spaced relation to the hollow bulb-shaped body.

3. Device for irradiating liquids more especially with ultra-violetrays, comprising in combination a hollow bulb-shaped body, :1cylindrical grid forming an extension of the latter, a source of lightrays arranged withinthe grid, wires for the supply of electric currentpassing through the said bulb-shaped body and being connected with thesaid source of light rays, and a vertically adjustable troughsurrounding the bulb-shaped body and pipgn at its lower end, for thepurpose speci- 4. A device as claimed in claim 2 further comprising acylindrical sleeve mounted around the cylindrical grid, for the purpose.

specified.

In testimony whereof I aflix my signature.

FRANZ HOFFMANN.

